The present invention relates to cutoff devices for cutting a roll formed continuous beam having a multi-curved longitudinal shape as it exits a roll former mill.
A known prior art cutoff device (see Heinz U.S. Pat. No. 5,305,635) is able to cut a (single radius) swept tubular continuous beam into beam segments. The beam segments each have a predetermined length and shape making them useful as bumper reinforcement beams. Recently, Shape Corporation employees have conceived of an apparatus and method involving a sweep station at the end of a roll former that allows a continuous beam to be given multiple/different sweeps. Beam segments can be cut from the continuous beam that have increasingly curved ends, thus providing beam segments matching the designed vehicle shape without the need for secondary processing to reform ends of the beam segment. This saves considerably by reducing secondary processing of the beam segments. A problem is that a continuous beam with multiple/different sweeps tends to oscillate up and down quite dramatically as a first curved shape first exits the sweep station and then as a second more-curved (or less curved) shape exits the sweep station, especially when the roll former is operated at significant line speeds. The cutoff device in Heinz '635 is not able to handle this oscillating movement when the movement is rapid and substantial.